For some three years running, electronic ignition systems have worked successfully in automotive applications. In almost all of the known systems it has been the desire of those skilled in the art to use zener diodes to protect the semiconductor circuit controlling the charging and discharging of an ignition coil from reverse current that would fail the semiconductor switching means.
It has been equally well known by those skilled in the art to use with a semiconductor ignition circuit a capacitor to protect against the transient generation of excessive E.M.F. induced by the collapse of a magnet field in a primary winding of an ignition coil.
Also, it has been proposed by those skilled in the art to limit or regulate the voltage across an ignition coil by means of gas discharge lamps to eliminate transient voltage peaks.
It is now the principle object of this invention to disclose to the art a circuit using two gas discharge tubes in series controlled by a capacitor so as to protect solid state devices and more importantly make it possible at the same time to increase energy available in a primary winding of an ignition coil.
These and other objects are obtained by a circuit comprising a transistor switch responsive to timing switch means, be it a set of breaker points or induction pick-ups as are now becoming more common, which are connected to a primary winding such that a parallel circuit of a capacitor and a series circuit of gas discharge tubes are interposed about different portions of the transistor to protect it and allow greater coil energy.
The various features and advantages of the present invention will become more apparent upon a consideration of the following description taken in conjunction with the accomanying drawings.